There are several different families of antibiotics that are commonly used to treat acne vulgaris. Each antibiotic family has its own unique chemical structure. Some antibiotic families are more active than others against the bacteria that contribute to acne symptoms (eg. Propionibacterium acnes).
Common Aminoglycoside Antibiotics: Neomycin (Neosporin), Amikacin (Amikin), Kanamycin (Kantrex), Streptomycin and Tobramycin (Tobrex). Frequency of Use For Treatment of Acne?: Rare. Frequency of Aminoglycoside Resistant P. acnes Bacteria: Very Common. (What does this mean?)
Aminoglycoside antibiotics tend to be ineffective treatments for acne vulgaris and are rarely used for this purpose. Aminoglycoside antibiotics are modified sugar molecules that are pimarily effective against gram-negative bacteria. There are many types of aminoglycosides and they are used extensively in both medical and scientific applications. Most of the aminoglycoside antibiotics work by inhibiting protein synthesis in susceptible bacteria. Amiglycosides are popular antibiotics for topical treatments (the primary ingredient in neosporin is neomycin, an aminoglycoside). P. acnes bacteria are generally very resistant to aminoglycosides. As a result, aminoglycoside antibiotics are almost never used in the treatment of acne vulgaris.
Cephalosporin Family Antibiotics
Common Cephalosporin Antibiotics:Cephalexin (Keflex), Cefadroxil (Duricef), Cefdinir (Omnicef), Cefoxitin (Mefoxin), Cefaclor (Ceclor), Ceftaroline (Teflaro) and Cefixime (Suprax) Frequency of Use For Treatment of Acne?: Occasional. Frequency of Cephalosporin Resistant P. acnes Bacteria: Rare. (What does this mean?)
Cephalosporin are occasionally used to treat moderate to severe acne symptoms (Acne Types: 3-4). Cephalosporins were first discovered by the Italian scientist Giuseppe Brotzu in 1948. Cephalosporins are another group of beta-lactam antibiotics, and are structurally related to the penicillins. In contrast to penicillins, cephalosporins are effective against a broader range of bacteria and are more resistant to a class of antibiotic resistance enzymes called “penicillinases”. In antibiotic susceptibility testing, cephalosporins were effective against P. acnes bacteria, but less so than penicillins. Research also indicates that cephalosporin treatment is only moderately effective at treating acne vulgaris.
Lincosamide Family Antibiotics
Common Lincosamide Antibiotics:Clindamycin (Cleocin) and Lincomycin (Lincocin). Frequency of Use For Treatment of Acne?: Very Common (especially as topical treatment). Frequency of Lincosamide Resistant P. acnes Bacteria: Occasional (but increasing). (What does this mean?)
Clindamycin, a lincosamide family antibiotic, is a common topical treatment for acne vulgaris. The antibacterial spectrum and resistance profile of clindamycin is similar to macrolide antibiotics, like erythromycin. Clindamycin resistant P. acnes bacteria are common in the United States and Europe.
Macrolide Family Antibiotics
Common Macrolide Antibiotics:Azithromycin (Zithromax), Erythromycin (E-Mycin), Clarithromycin (Biaxin), Josamycin (Josalid) and Roxithromycin (Roximycin). Frequency of Use For Treatment of Acne?: Very Common (especially as a topical treatment). Frequency of Macrolide Resistant P. acnes Bacteria: Occasional (but increasing). (What does this mean?)
Macrolides were first discovered in 1949 by Abelardo Aguilar and J. M. McGuire, who were both scientists working for Eli Lilly. Macrolides are a class of antibiotics known as “polyketide antibiotics”. They work by inhibiting protein synthesis in bacteria, which is similar to several other classes of antibiotics. Macrolides are commonly used to treat infections caused by Gram-positive bacteria (eg. Streptococcus pneumoniae) and are a popular choice for uncomplicated respiratory infections. In recent years the use of macrolide antibiotics has increased substantially, particularly the use of azithromycin. As a result, bacterial resistance to macrolide has increased as well. Topical macrolide antibiotic treatments are extremely popular in the treatment of acne vulgaris, paritcularly the use of erythromycin. However, P. acnes bacteria are becoming increasingly resistant to macrolides. In fact, recent antibiotic susceptibility testing in the United States and European Union suggest that the majority of P. acnes bacteria are now resistant to these antibiotics.
Common Penicillin Antibiotics: Benzylpenicillin (Penicillin G), Amoxicillin (Amoxil), Ampicillin (Polycillin), and Ampicillin + Clavulanic Acid (Augmentin). Frequency of Use For Treatment of Acne?: Occasional. Frequency of Penicillin Resistant P. acnes Bacteria: Rare (but increasing). (What does this mean?)
Penicillins were discovered in 1928 by the Scottish scientist and Nobel laureate, Alexander Fleming. This breakthrough revolutionized the treatment of bacterial infections and initiated the modern era of antibiotics. Penicillins are class of antibiotics called “beta-lactam antibiotics” and are used in the treatment of many types of bacterial infection. Penicillins work by damaging the cell wall of susceptible bacteria. They are most effective against gram positive bacteria, a group that includes the acne inducing Propionibacterium acnes. Antibiotic susceptibility testing has shown that most P. acnes bacteria are extremely sensitive to penicillin family antibiotics. However, penicillins are not commonly used in the treatment of acne, although research indicates that they can be quite effective.
Quinolones are a class of broad-spectrum antibiotics that were discovered by George Lesher in the 1960s. Quinolones inhibit bacterial growth by preventing bacteria from reading and duplicating their DNA. Quinolones are effective against both gram-negative and gram-positive bacteria, including P. acnes. Quinolones are commonly used in combination with other antibiotics, and are rarely used for long term treatments or prophylaxis. This is because bacteria can become resistant to quinolone easier than most other antibiotics. Small changes in the DNA code of susceptible bacteria can make them resistant to quinolones (most antibiotic resistance requires more substantial changes). This makes it easy for bacteria to spontaneously develop quinolone resistance. Quinolones also tend to have higher rates of side effects than other drugs. While P. acnes bacteria are generally susceptible to quinolone antibiotics, they are rarely used in the treatment of acne vulgaris. However, some topical quinolone treatments have shown good promise in acne treatment.
Common Rifamycin Antibiotics: Rifampicin (Rifampin), Rifabutin (Mycobutin) and Rifapentine (Priftin). Frequency of Use For Treatment of Acne?: Rare. Frequency of Rifamycin Resistant P. acnes Bacteria: Rare. (What does this mean?)
Rifamycins were discovered by the Italian scientist Piero Sensi and Israeli scientist Pinhas Margalith in 1957. Rifamycins work by preventing bacteria from reading their DNA (they block RNA synthesis). Rifamycins are important components of the combined antibiotic therapies used to treat tuberculosis. Because rifamycin is an essential part of anti-tuberculosis therapy, its use in the treatment of other infections has been restricted in some places. Bacterial resistance to rifamycins tend to develop faster than resistance to other antibiotics. Rifamycins are active against most P. acnes bacteria, but they are rarely used in the treatment of acne vulgaris. However, recent research has indicated that rifampicin (the most common rifamycin antibiotic) may be highly effective in improving acne symptoms. These researchers recommended that rifampicin be combined with a secondary antibiotic to minimize the development of antibiotic resistance.
Co-trimoxazole is a combination of two antibiotics that work together to inhibit folic acid synthesis in bacteria. Co-trimoxazole is a 5:1 blend of sulfamethoxazole and trimethoprim. Sulfamethoxazole is a “sulfa drug” which were among the first types of antibiotics widely marketed. Sulfa drugs were extremely popular in the 1930’s, but their use decreased as newer antibiotics became available. Trimethoprim is a “dihydrofolate reductase inhibitor” that inactivates the enzyme that bacteria use to synthesize folic acid. Antibiotic susceptibility testing shows that most P. acnes bacteria are susceptible to co-trimoxazole. For many individuals, oral co-trimoxazole has been shown to produce dramatic improvements in acne symtpoms, particularly in cases of severe and/or inflammatory acne. However, co-trimoxazole is not commonly prescribed for the treatment of acne vulgaris. This is primarily because of two factors. First, allergic reactions to sulfa drugs are more common and more severe than many other antibiotics. Second, the use of co-trimoxazole in the treatment of acne is considered “off-label” in many places, including the United States. As a result, many physicians do not feel comfortable considering co-trimoxazole for the treatment of acne. But for those patients without allergies to the medication, co-trimoxazole treatments may yield substantial improvements in the severity of acne symptoms.
Tetracyclines were discovered in the 1940s by the plant scientist Benjamin Duggar. Tetracyclines are a class of broad-spectrum antibiotics that work by inhibiting protein synthesis in susceptible bacteria. Tetracyclines were once extremely popular for the treatment of a wide range of infections, but in the last thirty years their effectiveness has declined greatly due to the spread of tetracycline resistant bacteria. Tetracycline antibiotics are the oral antibiotic of choice for many physicians in the treatment of acne vulgaris. However, antibiotic susceptibility testing clearly shows that tetracycline resistant P. acnes bacteria are very common, particularly in industrialized countries. Additionally, both research data and anecdotal evidence indicates that tetracyclines are often ineffective in the treatment of acne vulgaris. The disconnect between which antibiotics are most commonly prescribed for acne, and which antibiotics are most effective is likely due to the fact that many of the prescribing guidelines now in use for the treatment of acne were developed many years ago, when the patterns of antibiotic resistance in bacteria were different.
Other Antibiotic Families
Carbapenem Family Antibiotics: Imipenem and Meropenem.
Chloramphenicol Family Antibiotics: Chloramphenicol.
Chloramphenicol is an inexpensive, broad spectrum antibiotic that is used in many topical preparations. It is most commonly used in anti-bacterial eye drops. Usually, P. acnes bacteria is moderately susceptible to chloramphenicol. Common name: Unison.
Fusidic acid is an antibiotic that prevents bacteria from synthesizing proteins. There is some evidence that fusidic acid may be helpful in the treatment of acne, although it is usually combined with a secondary antibiotic for treatment. Fusidic acid is primarily available as a topical treatment.
Glycopeptide Family Antibiotics: Teicoplanin and Vancomycin.
Lipopeptide Family Antibiotics: Daptomycin (Cubicin)
Daptomycin is a relatively new lipopeptide antibiotic that is used to treat infections caused by Gram-positive bacteria. It is not widely available.
Nitroimidazole Family Antibiotics: Metronidazole (Flagyl).
Oxazolidinone Family Antibiotics: Linezolid (Zyvox).
Mupirocin is a topical antibiotic that is active against a range of bacteria. However, Propionibacterium acnes appears to be naturally resistant to this particular antibiotic. It prevents bacteria from utilizing the amino acid isoleucine. Bacterial resistance to mupirocin can develop quickly.
Retapamulin is a newly developed antibiotic. Several studies have indicated that retapamulin (Altabax) is an effective topical treatment for acne vulgaris.
Polypeptide Family Antibiotics: Bacitracin and Polymyxin B.
The two most common polypeptide antibiotics are bacitracin and polymixin B. Both are ingredients in the standard Neosporin (along with neomycin). Both drugs work by disrupting the cell walls and cell membranes of susceptible bacteria. They are used primarily as topical antibiotics. Neither antibiotic is particularly effective in the treatment of acne vulgaris.
Streptogramin Family Antibiotics: Pristinamycin (Synercid).